NL8101847A - METHOD FOR CONVERTING SOLID FUELS TO HYDROCARBONS AND OTHER VALUABLE PRODUCTS. - Google Patents

Description

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Process for converting solid fuels to hydrocarbons and other valuable products.

The invention relates to the conversion of solid fuels to hydrocarbons and other valuable products using a special reagent.

Such a method is known, for example, from patent application 80.04439. The conversion is based on a reaction of the reagent with oxygen, nitrogen and sulfur in the fuel, in the presence of steam. Furthermore, the said patent application describes under different conditions, in terms of temperatures, reactants, degree of carbonization of the fuel and reaction steps. The special reagent is generally a hydrosulfide, sulfide or polysulfide of an alkali metal or a mixture thereof, optionally stabilized to a less hydrolyzed polysulfide using sulfur.

It has now been found according to the invention that these reagents can be stabilized by using hydrogen sulfides in the reaction. It has also been found that the method can be extended at various points.

In general, the invention includes a conversion of solid fuels to various useful products derived therefrom, either substantially gaseous products or gaseous and liquid products in different proportions, or mainly liquid products, in combination with a suitable reagent recovery and water sulfide, which is used in the process. The invention further includes the conversion of the gaseous products to other distillates. for example, it relates in particular to the conversion of solid fuels to desired conversion products, such as liquid or gaseous hydrocarbons, by converting the fuel into one 8101847 * - *

X

- more stages with a specific reagent therefor, which may be the same or different in each stage, always in the presence of water or steam and hydrogen sulfide.

The process is performed at a low to moderate temperature under a pressure between atmospheric pressure and gauge pressure of less than 0.35 kg / cm.

The invention further relates to the conversion of solid fuels into various product fractions, namely mainly gaseous product fractions, gaseous and liquid product fractions or mainly liquid fractions, using specific reagents, the solid fuel being present in the presence of this reagent, water, steam and hydrogen sulfide and any sulfur are converted to useful decomposition products. In one stage operation 15, these degradation products are either mainly gaseous hydrocarbons, or mainly liquid hydrocarbons, or a mixture of gaseous and light liquid products ("light" here means liquid with a low boiling point). one or more additional steps in the presence of different reagents, steam or hydrogen sulfide are converted into liquid distillates. Finally, the "solid fuel when present-h" gives. "Vaiï is the reagent, hydrogen sulfide and steam and at a high temperature. rise to the formation of some hydrogen.

It is becoming increasingly clear that energy resources such as oil and natural gas are becoming so "exhausted" so quickly that intensive efforts must be made to address future X.

V r "......" "- - T- -" unn.iui .. »-,« - * ·· "1: 8101847 -3- ί 4 Demand for replacement energy sources, fuels or chemical starting materials . Coal is still readily available from which hydrocarbon materials could be extracted, but so far no economic method without high capital investment is available to prepare hydrocarbons from coal. Although various methods are known for gasifying coal at high temperatures, such as temperatures above 600 ° C, and high pressures, for example above 25 atmospheres, no method has yet been known, with which coal is produced at lower temperatures and under low pressure in hydrocarbons derived therefrom. could be converted.

Reference can be made for the prior art. to U.S. Patents 1,300,816, 1,413,005, 15 1,729,943, 1,904,586, 1,938,672, 1,974,724, 2,145,657, 2,950,245, 3,112,257, 3,185,641, 3,252,774, 3,368 .875, 3,354,081, 3,382,168, 3,483,119, 3,553,279, 3,565,792, 3,617,529, 3,663,431, 3,745,109, 3,787,315, 3,788,978, 3,816,298, 3,926,775 , 3,933,475, 3,944,480, 3,960,513, 20 3,957,503, 4,003,823, 4,007,109, 4,018,572, 4,030,893, 4,057,422, 4,078,917, 4,119,528, 4,147,611, 4,147,612, 4,155,717, 4,160,721 and 4,210,526, as well as the following references:

Letoffe et al., Determination des Enthalpies de 25 Formation des Polysulfures de Potassium, Journal de Chimie Physique, 71, pp. 427-430, 1974?

John S. Thomas and A. Rule (other articles of the series were written by Thomas and Riding), The Poly-sulfides of the Alkali Metals, Journal Chemical Soc., Vol. 80 3, p. 1063 et seq., 1973;

Blitz and Wilke-Dorfurt, Z. Anorg. Chem., Vol. 48, p. 297, 1906 (see also "Ber., 53, p. 43, 1905); Yan Krevel et al., Fuel, 38, 256, 1959; B.K. Mazumdar et al., Fuel, 41, 121, 1962; Hugot, Ann. Chim Phys., 21, 72, 1900? W. Klemm, Z. Anorg. Chem., Pp. 24.1, 281, 1939; F.W. Bergstrom, J. Amer. Chem. Soc., 147, 1926; 8101847 jfi, ** V, -4- F. Feher and H. Berthold, Z. Anorg. Chem., P.

247, 1953;

Thomas and Rule, J. Chem. Soc., 2819, 1914; R.L. Erbeck, Dissert, Abstract, Ann Arbor, Mich.

5 3254, 21, 1961;

Renegade and Costeanu, Bull. Soc. Chim., 15, 721, 1911;

Sabbathier, Ann '. Chim. Phys. 22.5, 1881;

Marrony, "J. Chim." Phys., 56, 214, 221, 1959; 10 Mrs. Aline Auroux, "C.R. Acad. Soc. Paris, 274 pp. 1297 to 1300, March 1972; Küster and Herberlein "Beitrage zur Kenntnise der Polysulfide'1 · Z. Anorg. Chem., Pp. 53-84, November 1904.

15

It has now been found that if solid fuels are treated with a special reagent, they are used in the presence of this reagent and in the presence of water and / or steam and. hydrogen sulfide can be converted to various hydrocarbon fractions or substantially gaseous hydrocarbon fractions of 1 to 5 carbon atoms (C 1 to C 2), for example, methane, ethane, ethylene, etc., or mainly liquid distillates or mixtures, which are limited to these limits for practical purposes. Hydrogen is also formed as a by-product.

At higher temperatures, more or mainly gaseous hydrocarbons will be formed, while, in addition, if another reagent is used in a different reactor, the gaseous hydrocarbons can be further reacted in the presence of steam and hydrogen sulfide to obtain other hydrocarbons, such as liquid or gaseous hydrocarbons. It has also been found that by altering the reagent and using apparently anhydrous and eutectic mixtures of sulfides, as will be further described below, the boyen conditions can be reversed.

Furthermore, it was surprisingly found that the addition of hydrogen sulfide is considerably more favorable than the addition of sulfur, as described in the above-referenced patent application, because hydrogen sulfide more effectively stabilizes the reagent and contributes to the conversion of the thiosulfate or tetrathionate 5 to form 2 thiosulfate ions.

In the presence of water, some degradation of KHS to K2S occurs. This breakdown is partial. In the hydrogenation of solid fuel, therefore, both KHS and K2S must be present. When sulfur is added, a less hydrolysed and therefore more stable to water polysulfide, for example potassium pentasulfide, is also formed. Hydrogen sulfide not only improves stabilization but also reduces the amount of reagent required.

It has further been found that if mixtures of alkali sulfides are reacted, they can be added to the fuel to facilitate conversion in the liquid state, for example, mixtures of polysulfides or hydrates thereof.

When the K2S and its various polysulfides react with the fuel, they mainly attack the oxygen, sulfur and nitrogen present in the fuel in bonded form in order to extract these components from the fuel w Are, in addition to the reagent, steam or water and hydrogen -25 sulfide present, the bonds of various components of the fuel are broken when extracting oxygen, nitrogen and sulfur, making it possible to introduce hydrogen from the water or hydrogen sulfide, so that hydroaromatic, aromatic and aliphatic compounds with a short chain can be formed.

The attack conditions can be adjusted to vary from those conditions, the product being essentially. gas is formed, to conditions where the product is essentially a liquid, which adjustment is determined by the reagent used, respectively. the reagents used and. the operating conditions.

The invention will be further elucidated with reference to the annexed drawing, in which the conversion reaction and 8101847> * -β- "I -".

recovery of products including recovery of hydrogen sulfide is schematically shown.

In the process, the system is first freed from oxygen by purging with an inert gas, such as nitrogen or helium, which inert purging flow may no longer be required once the desired operating temperature has been reached and hydrogen sulfide or steam and hydrogen sulfide in the system is led. Hydrogen sulfide can be supplied through the steam line.

The drawing shows a reactor 22, to which solid fuel, in particular coal or peat, can be supplied via line 1, reagent via line 2, H20 via line 3 and H2S via line 4.

The reactor is kept at an elevated temperature during the reaction, in particular a temperature of 350-390 ° C. The reaction gases released during the reaction are led via line 5 to a condenser 26, which is surrounded by a cooling man 24, to which cold water is supplied via line 6 and from which the hot water is discharged via line 7. The cooled product stream obtained in the condenser goes via conduit 8 to the bottom vessel of condenser 27 from which the initial and heavier products are discharged via conduit 9, while the gaseous products via -. line 10 to a vessel 30 containing water and alkanol (in particular methanol or ethanol).

The yat 30 receives water or alkanol from the reactor 22 when a reagent solubilized in alkanol is used. The mixture of water and alcohol in the vessel 30 is maintained at a temperature below the bump point of the mixture so that the lighter gases such as the to C-hydrocarbons and the hydrogen sulfide pass through the vessel.

The lighter gases are passed via line 11 to a vessel 31 $, the contents of which are cooled to a temperature of about -35 ° C, at which temperature the C 2 -35 and C 2 hydrocarbon feri are liquid, which are then passed via line 12 be won. Although the majority of the C 2 and C 2 fractions in the vessel 31 are removed, a portion still passes through line 13 to a vessel 32, in which they are taken together with the C 7 -fraction- at -30 ° C in ethanol or methanol are separated to be recovered via line 14.

The vessel 32 is supplied with additional alcohol via line 15. The vessel 32 is provided at the top with a glass frit disc 33 by means of which a possible mist is separated from the gaseous components. Under these conditions, substantially only H 2 S and the C 2 and C 2 and C 2 fractions are present in the gas stream, which is then fed to a vessel containing KOH and alcohol, especially ethanol or methanol, in aqueous solution. In the vessel, the hydrogen sulfide is used to reconstitute the reagent, which is obtained as a precipitate 17 and is recovered via line 18, while the light gases mainly consisting of the C 1 and C 2 fractions enter the vessel. leave the top via line 19. About 97% or more of the H 2 S is recovered mainly as KHS and can be reused as a reagent. No H2S is released into the atmosphere. The alcohol-water mixture from the vessel 30 is used to replenish the alcohol which is entrained from the vessel 35 via line 18. However, this mixture must be cooled using a heat exchanger 36. It will be understood that the mixture of water and alcohol which is discharged from the vessel 30 via line 20 can be removed from the system in the case of an excess via the three-way cock 21.

As noted above, the hydrogen sulfide can be introduced into the reactor as a separate stream or together with steam. If the hydrogen sulfide is introduced together with steam, it can take place at temperatures of about 135 ° C and above and will usually take place at temperatures of 170-19 ° C, if steam is used, such that the hydrogen sulfide with the steam is introduced. Steam is only introduced into the reaction vessel when the mixture of methanol and water used for feeding the reagent 35 has been expelled, because the mixture of water and methanol cannot withstand the temperature within the specific range used during the distillation . Hydrogen sulfide is present 8101847 * * -8- u— ** · from the start of the reaction.

When introducing the steam or the steam with continued introduction of hydrogen sulfide, the fuels such as lignite and flame coal show different distillation points in the production of significant amounts of gaseous hydrocarbon, depending on their inherent composition. fabrics.

The gas production increases considerably when a temperature of 360 ° C is reached, while at a final temperature between 380 ° C and 450 ° C a very rapid gas production occurs, with some hydrogen developing. Carbonyl sulfide is also formed at a temperature of 360 to 380 ° C. For flame coal, for example, 4.7% by weight of the total amount of carbonaceous gas may consist of carbonyl sulfide. When using hydrogen sulfide, the carbonyl sulfide production appears to be suppressed if all conditions are otherwise kept the same.

Without being bound by any particular theory, it is believed that in the reactions the water and hydrogen sulfide molecules provide hydrogen which reacts with the fuel in such a way that it is deoxygenated, desulfurized or denitrified.

It is therefore necessary for the purpose of the invention,. 1 that oxygen is present in the fuel / although the benefits are also achieved, inks sulfur and nitrogen (in the coal) are present, eg. in the form of organic sulfur or organic nitrogen compounds. In addition, higher carbonization, such as fatty coal, is less easily converted to gaseous hydrocarbons, although this is nevertheless possible, as described further below, when the reaction scheme is suitably modified.

The invention further preferably relates to the gasification of brine and flame coals, although all types of fuels can be gasified or converted into liquid products, while even wood can be gasified in the form of chips. In addition, wood (cellulose, lignin, sugars, etc.) can be converted into gaseous or liquid products.

An anthracite with a carbon content of 92%, when partially oxidized, can be easily converted to liquid and gaseous conversion products.

If the potassium is converted to hydrosulfide in the ash fraction of the fuel, no loss of potassium hydrosulfide is experienced and the reagent halan for the reaction is very favorable whether carried out batchwise or continuously. In addition, when stabilizing the reagent with hydrogen sulfide, the amount of reagent used can be reduced, and the excess sulfur and potassium from the fuel can be utilized, for example, for the production of reagent or hydrogen sulfide.

However, it should be noted that in general sufficient amounts of sulfur, hydrogen sulfide, hydrosulfide or polysulfide should be present to absorb the sulfur released from the reagent or the oxygen or sulfur released from the fuel during deoxygenation, thereby preventing that the expelled sulfur 20 will give rise to a dehydrogenation of the coal at temperatures above 175 ° C. Likewise, the identity of the various reagents above 325 ° C must be maintained because an increase in temperature above this value would otherwise cause slow dehydrogenation of the fuel by the alkali metal hydroxide melt. Since sulfur gives rise to the formation of polysulfides and alkali metal polysulfide is less readily hydrolyzable as its sulfur content increases, the decomposition by steam (or other water} of the hydrolysis product, ie the hydrosulfide, is thereby prevented by the addition of hydrogen sulfide. however, better stabilization is achieved, as will be explained later in this description.

The hydrogen sulfide / which is developed upon addition of the elemental sulfur to the alkanol solution of alkali metal hydrosulfide and the sulfur displaced by oxygen during the conversion of fuel to hydrocarbons is utilized to form further alkali 8101847 * + -10-L Metal hydrosulfide from the alkali metal hydroxide recycled in the process. Therefore, since hydrogen sulfide is also introduced into the reactor (s) to stabilize the reagent, the hydrogen sulfide may be present in excess of the amount required for the reaction.

Part of the potassium hydrosulfide decomposes after hydrolysis to potassium hydroxide and hydrogen sulfide.

This potassium hydroxide forms a medium at temperatures of 360 ° C and higher, whereby the calcium carbonate of the limestone (in the ash content of the fuel) reacts with the potassium sulphate (from the residue of the reagent I 'to form fcium sulphate and a mixture of potassium hydroxide and potassium carbonate The potassium content of the ash ash components of the fuel is also extracted in the hydroxide form.

As mentioned above, steam is applied at a temperature at which it is desired to carry out the reaction, that is to say depending on the type of fuel and the degree of decomposition thereof. as well as the desired product. Water present in the fuel also forms a source of water and / or steam.

As the sulfur content of the reagent is increased, namely, by sulfur present in the fuel, by added elemental sulfur or from the hydrosulfide, the reaction temperature is lowered. For example, a reaction temperature of 380 ° C is lowered to 3.50 ° C if the sulfur balance is representative of a theoretically formed compound and is maintained during the reaction conditions. A consequence of this phenomenon is that larger molecules are formed, for example pentanes, that is, U "isopentane. and pentane.

Furthermore, the degree of carbonization of the fuel influences the composition of the distillate and the higher the degree of carbonization of the fuel, the greater the amount of liquid distillates will be formed under equivalent conditions, for example, using 8101847-11 the theoretical K2S2. connection at the same temperature conditions.

When the temperature is changed, the composition of the product naturally also changes. As already explained above, the composition of the product will also change when the amount of sulfur in the reagent is changed.

On the basis of the above, it is thus possible to change the temperature and / or the sulfur content of the reagent to obtain the desired product fractions, use mixtures of reagents, for example liquid or dissolved form thereof, coal of a different degree of coalification use and / or use of a recirculation of alcohol-absorbed distillates.

The variations described above are subject to the following requirements: temperatures from 425 ° C to 450 ° C, but then the distillation starts at 40 ° C to 50 ° C? sulfur content in the reagent (e.g. for potassium). K2S but this sulfur content can reach K2S ^; addition of sulfur or hydrogen sulfide; mixture of these reagents; liquid or solid state of the reagents; contacting a product stream with reagents of a different composition, including hydrogen sulfide? and degree of cooling of the fuel (the carbonization range from brown coal to fat coal is desired). When used to anthracite, the results are less favorable, although a distillate can be obtained at + 380 ° C and using a reagent such as S ^. Partial oxidation of a fuel can be so high. degree of carbonization is also useful.

In addition, the amount of the recycled material can also be varied. For example, up to temperatures of about 280 ° C, the composition of the product can be moved toward a composition which is a liquid distillate with a boiling point below about 180 ° C. At a reaction temperature of up to about 310 ° C, paraffin distillates are formed when the above-described alpha alcohol recirculation to the reaction vessel is used. In this recirculation, as noted above, I / Λ 8101847-12- / water / that is to say, steam must be present at a temperature of about 135 ° C (and higher) and water sulfide for the reaction to take place in a favorable manner.

At the start of the whey process under about ambient conditions (and increase in temperature), elemental sulfur or preferably hydrogen · *; sulfide added to the fuel or to the reagent to obtain the selected sulfur content for the reagent. Under these conditions, during the reaction of the sulfur and the reagent in the system, it is formed from the gas stream and the washing system is removed before the reagent is reassembled, as illustrated by the accompanying drawing. When the temperature is raised and no steam is used, all possible hydrogenation of the fuel takes place thanks to the water content in the fuel or the reagent. Steam can be added at about 135 ° C if light distillates are desired. Typically, however, steam is added at about the temperature that a hydrate of the reagent begins to reform or convert it to a lower hydrate. For a potassium-based reagent, the temperature for adding steam is selected at about 170 ° C.

In summary, it can therefore be noted that when "oxygen as well as nitrogen and organic sulfur is removed, water or, to a lesser extent, hydrogen sulfide (which is continuously formed by the contact between water and reagents) supplies hydrogen to the fuel at the site. where the coal is deoxygenated, desulfurized or denitrified; nitrogen is mainly released as ammonia; Sulfur liberated from alkali metal (e.g. potassium) polysulphide and forms a mercaptan at lower temperatures with the alkanol used as solvent. Mercaptans are absorbed in alcohol and in the KOH-containing alcohol solution. The total reaction proceeds via a reduction of the gaseous hydrogen sulfide to sulfur and water followed by the reaction of the sulfur with the KOH to form the potassium thiosulfate and the potassium sulfide. The potassium sulfide can then take up further sulfur from the hydrogen sulfide 81018 47-13 to form potassium polysulfide, which are the reagents used in the reaction.

The hydrocarbon compositions, ie the gaseous fractions obtained at different temperatures, can be further treated, for example in another reactor with a reagent of a different composition, ie a reagent, with a higher sulfur content and at a lower temperature than in the first stage, the reaction temperature being from 340 ° C to 390 ° C, for example, the temperature in the next stage may be from 280 ° C to 340 ° G at a higher sulfur content in the reagent; in a third stage, the temperature may be 225 ° C to 280 ° C or 180 ° C to 225 ° C. Since the dehydrogenation reaction occurs competitively with the hydrogenation reaction, this gives rise to increasing sulfur content in the reagent and in the presence of sulfur. a dehydrogenation of the product stream, which is initially gaseous. This stream can then be treated to obtain the product of the desired composition, ie the desired specific gravity for a predetermined product. In other words, the initial gaseous products are reformed into products which are in demand.

As noted above, the addition of hydrogen sulfide to the reagent, that is, the alkali metal sulfides, mixtures of sulfides, hydrates thereof, etc., provides an improvement in the process during the hydrogenation step of the fuel or fuel product. . By the addition of hydrogen sulfide, it appears that the selected reagent is kept in a stable state, so that a reaction once started with that special reagent or reagent mixture from the same starting material and when all other conditions are kept constant, with little variation. will provide substantially the same products or mixtures of products. Therefore, proper stepwise adjustment of the reagents, their compositions for each of the steps, temperature conditions and of the addition of 81 01 847-14 water will be further improved in the above-described process by the addition of hydrogen sulfide, so that now a wider range of products, selected prodkt mixtures and a more precise degree of hydrogenation (if desired including dehydrogenation of a product stream or product streams). to be.

The correct alkali metal sulfides, mixtures, of sulfides and mixtures of. Hydrates of.

The sulfides obtain the desired stability (of the reagent) due to the presence of hydrogen-sulfide and will provide the selected product. Thus, if the reagent is properly maintained in the "active" state (of the reagent) by the addition of hydrogen sulfide, the following advantages are achieved: reduced amount of reagent, better yields, and better control of. the product.

The reasons for the addition of hydrogen sulfide are evident from the following reactions given by way of illustration.

1. 4KOH + 4H2S - »4KHS + 4H20 20 If sulfur from the coal is present then 2. 4S + 6K0H -» K2S2 ° 3 + 2K2S + · 3Η2 ° then.

3. K2S2Os + 3H2S - $ K2S5 + 3E20 teinffile - the decomposition of K2S2 proceeds as follows:: - - 25 4. 4K2S2 + 8H20 - * 4 KOH + 4KHS + 4S + 4H20.

Thus, if H 2 S is present, the KOH is converted to KHS, while if any KOH forms the thiosulfate, this thiosulfate is subsequently converted to K 2 S 4.

Further reactions are as follows: 30 5. K2S5 - »K2S4 + S (above 300 ° C) 6. K2S4 —— * K2S3 + S (above 460 ° C)

7. KHS + K2S + 3H20 - 3KOH. + 2H2S

8. K2S + 2020 -KOH + KHS

9. KHS + H20 -? H2S + KÓH

35 10. KHS + KOH -? K2S. xI ^ O

(x can, for example, have a value of 2.5, etc., depending on the temperature).

Thus, a sufficient amount of H 2 S should be present to maintain (by the mass action reactions) a state in which the reagent is stable, i.e., the hydrogen sulfide prevents the reagent from hydrolyzing. when sulfur is taken up, either (if released) from the fuel or from the reagent. Moreover, the thiosulfate developed by the oxygen present in the fuel is regenerated during the reaction into the desired K2S3 sulfate. The reagent is thus maintained by the desired hydrolysis.

.10 Among the various reagents, the following are preferred in view of their stability and sulfur-absorbing capacity: KHS, NaHS, K2S, K2S2, K2 ^ 3 ', of which in particular in the order of preference K2S2, K2S and then should be called. The other sulfides 15 exhibit instability at their melting points, e.g. image Na2S2 at 445 ° C, Na2S4 at 275 ° C or release sulfur at 760 mmHg, for example K2S2 at 300 ° C yields K2S4 + S; K2S4 at 460 ° C K2S3 + S and K2S3 at 780 ° C K2S2 + S.

The melting points of the above-mentioned alkali metal sulfides are as follows: for K2S at 948 ° C, K2S2 at 470 ° C; K2S3 at 279 ° C (pour point); K2S4 at 145 ° C; K2S5 at 206 ° C; and K2Sg at 190 ° C. The melting points for mixtures of the sulfides (pure or eutectic mixtures) are as follows: - · · '' '· "for K2S' - K2S ^ the melting point is 350 ° Cr for K2S2 -25 K2S3 225 ° C / for K2S3 - K2S4 about 110 ° C. and for K2S4 -K2S5 183 ° C. Based on the various data above, suitable temperature conditions are chosen as determined by the decomposition and / or melting point properties to use a solid reagent or a stable liquid reagent, for example to coat the fuel The various hydrates of the alkali metal sulfides naturally also have various melting and / or decomposition points, which of course suddenly applies to the eutectic mixtures These temperature values can easily be determined thermographically, such as. those skilled in the art are known.

The fuel conversion process proceeds without instability (of the reagent, i.e. instability) 8101847 * * -16-. The reagent, that is, instability of alkali metal sulphide hydrate, because the hydrogenation of the fuel is preferable to the decomposition of the reagent and the addition of hydrogen sulphide contributes to stabilizing the reagent. While the reaction with the fuel will proceed in the presence of a sufficient amount of the reagent, the addition of hydrogen sulfide also reduces the necessary amount of the reagent because the reagent is in one. 1Ό is in a more stable form, so that the working method is also improved on this basis. By using hydrogen sulfide, the yield of the product is at least doubled if all other conditions are kept the same.

Generally, the addition of hydrogen sulfide will take place on a space velocity basis and will usually be in the range of about 10 ml / min to 30 ml / min per liter of the reactor space, for example usually about 20 ml / min liter. Expressed on another basis, 20 per 1000 ml of water, which is removed in the hydrogenation reaction, E 2 S is added in an amount of half a gram or less. In describing the various sulphides and their decomposition temperatures including * ·· "-;" ·; - · in addition to this the re-actions are the US patent -......

25 script 4.2X0.526 relevant.

At the maximum operating temperature applied, for example 450 ° C, K2Sj. release sulfur (which is a useful phenomenon, as explained with regard to the dehydrogenation of further treatment 30 'streams). Since the decomposition temperatures are lowered at lower pressures, the conversion of fuel under atmospheric pressure is perfectly feasible, although some advantage is achieved by operating under elevated pressures, for example above 5 atmospheres, but the additional cost and further necessary measures make this a less desirable embodiment of the coal conversion process. Thus, for practical purposes, the pressure conditions employed may range from about atmospheres to about 5 atmospheres, although operating under atmospheric pressure is preferred.

Although the reaction mass of fuel and reagent can be stirred appropriately, it is preferable to pre-coat the fuel with a reagent in the absence of oxygen because oxygen tends to destroy the reagent.

In this connection, it has also proved useful to use a liquid or a dissolved reagent. Liquid-10 yet. stable reagents can be used to coat fuel at or above the appropriate melting point of the selected reagent or of the selected liquid eutectic mixture thereof.

For example, a mixture of - K2S4 above 110 ° C in the liquid state can be used to coat fuel. Glycerol has proven to be very useful as a solvent for the above reagent. Any solvent in which the sulfides will dissolve and which will not adversely affect their activity can be used. About 88 g of KHS are dissolved in glycerol to a total solution of 200 ml. When the mixture is heated to 175 ° C (glycerol will decompose above 190 ° C), H2 O is expelled from the mixture of dissolved KHS * so that the mixture will then contain K2S.xH20. Oxygen is also excluded from this reaction mixture. This mixture can then be easily used to coat fuel and thus serves as a reagent.

Since the rigor of the attack of sulfur, nitrogen and oxygen in the fuel is a function of the composition of the reagent and the amount thereof, the following points should be mentioned. The conversion of fuel to gaseous compounds takes place when the degradation of the fuel, ie the attack of the fuel by the reagent, is the most rigorous. Less rigorous degradation yields * lighter distillates. At 175 ° C, sulfur begins to dehydrate the fuel and therefore the presence of sulfur for fuel conversion is not desirable. Under this circumstance- 8101847 *? A stable reagent is therefore used today. For reforming, that is to say dehydrogenation and reaction of dehydrogenated components with one another, it is important for the reaction that it is thereby possible to obtain preselected liquids with different boiling points (or a preselected specific weight by weight. Obtained gases are, of course, an ideal starting material for hydrocarbon reforming. As has already been stated above, the .10 degree of carbonization of the fuel also influences the reactions. For a more complete gasification, the amount of sulfur in the reagent is reduced. For example, K2S15 is used, while K2Sg is used for less rigorous attack. This applies in particular to peat, which, when reacted with K2S1, mainly naphthalene. supplies.

The above-described explanation of the invention and the method is further described by means of the examples, which do not limit the invention, but merely illustrate an embodiment thereof.

Example I

'; Ï "" ςν:' · '·' ·; * *> '' '···:' One-touch tank 'with a capacity of 3.8 liters 25 is provided with a steam valve , heating coolers, a thermocouple, a stirrer and a discharge pipe for the reaction gases. Hydrogen sulfide is mixed with the. steam added but can also be added separately. The products are collected in a suitably cooled condenser while the gases are collected, as illustrated by the accompanying drawing.

800 g of Kentucky Coal No. 9, which was kept under a helium atmosphere in the described vessel, became a "liquid mixture of an E 2 S. attached.

The amount of the reagent mixture added was 2 moles, that is, 1 mole of each component. The J. mol K2S3 was obtained from a mixture of K ^ S and K2S ^ dissolved in water and adjusted to the empirical formula K2S3 * Further 8101847 -19- 4 g KOH was added / which served to remove the NH ^ under the operating conditions. to float. The mixture was stirred to coat the coal particles with the reagent.

After this, steam was added along with H2S

in an amount of 80 ml / min at a temperature of 50 ° C. The reaction was exothermic but the temperature was not allowed to rise above 450 ° C, but kept as much as possible at about 350 ° C to 390 ° C. The steam was added at 135 ° C at a rate equivalent to the hydrocarbon effluent or 130% thereof. The recovered product was a clear amber red solution which, when treated under the same conditions with 19 g KHS to 240 ° C, distilled completely to a water-clear liquid hydrocarbon distillate (perfectly clear hydrocarbon) and had a water-like viscosity. A total of 324 ml of distillate including 12 liters (under standardized temperature and pressure conditions) of gas were recovered during the first reaction step. The product showed the following analysis:

Cooking range

Initial boiling point 82.2 ° C

10% - 237.8 ° C

- · · '·. ·' - · * * - -> - - ··· -; 20% - 248.3 ° C · -. · "----- 1 - · - · ·. . .

25% - 252.2 ° C

40% - 255.6 ° C 50% - 260.0 ° C 60% - .264.4 ° C 70% - 272.2 ° C 30 80% - 281.1 ° C

90% - 294.4 ° C 95% r 311.1 ° C 98.6% 1 333.3 ° C

(1.4% residue - heavy liquid).

Example II

In order to demonstrate the effectiveness of the addition of H2S, 110 g of fat coals (on a dry ash-free basis) were placed in a reaction vessel, as described above / with solid NaHS (technical grade) or KHS ( dissolved in water) were reacted with addition of H 2 S at a rate of 80 ml / min and 200 ml of helium. Steam was added at a temperature above 137 ° C at a rate corresponding to 130% of the removal of hydrocarbon condensate. By adding KOH, reactions with ammonia were suppressed in the reactor and the ammonia was expelled. The reaction became exothermic at 390 ° C. 10 252 liters of gas and 70 ml of liquid hydrocarbon condensate were obtained before the reaction assumed an exothermic character above 390 ° C in the test. .

When conducting brown coal tests with addition and without addition of H 2 S, the yields were more than double for the test adding H 2 S. The reagent described in Example 1 was also used as the other reagent. The reaction also became exothermic above 390 ° C.

About 3 moles of H 2 S are required per mol formed K2S2 ° 3. Furthermore, about 48 g of coal-derived oxygen is consumed when 1 mole of K2S2 ° 3 is formed.

Wood is approximately 42% oxygen and anthracite approximately 2%. Between these limits, on a basis of the above-mentioned reaction H2S is added up to such a maximum amount, because other competing reactions occur. The above is a rough guideline with regard to the amount of H 2 S required, but in practice smaller amounts are used, for example, thanks to the main side reaction of two atoms of hydrogen, which combine with oxygen to form water.

When KHS and / or NaHS are used they give rise to large amounts of gas and the reaction becomes exothermic above 390 ° C. K2S2 · 5H20 + K2S (empirical, based on equal molar amounts of K2S. 5H2Q 35 and ^ S ^) gives rise to little gas and significant amounts of liquid condensate from the same starting material, but the reaction is from the beginning, that is, about 50 ° C, exothermic and the reaction appears to be self-sustaining at 81 018 47 -21- 390 ° C with low heat input.

K2S2 (provide a melt of I5S. 5H2 O plus sulfur) mixed with an equal amount of K2S (obtained from a hot aqueous KOH solution plus sulfur in a ratio of 6K0H + 4S) as a reagent gives rise to liquid distillate and gas. The reaction becomes exothermic at 240 ° C when used by the same starting material. In all three cases, the starting material consisted of Kentucky Fat Coal No. 9, which passed a screen of 0.074 mm-10 mesh openings, and the reaction conditions were otherwise identical, i.e., steam, H 2 S, and helium were used, as above described. From the foregoing it appears that it is possible to obtain gas, gas and distillates or mainly distillates, as well as the very favorable character of the exothermic reactions. During these exothermic reactions, negligible amounts of CO and CO2 are generated. No hydrogen sulfide was detectable in the gas streams after washing. Apparently, no COS was formed.

The above is further elucidated by means of the following example.

Example III

For Kentucky Fat Coal No. 9, the following reagent was used: · - · (D · k2s.5h20- + S · ·. 25 theoretical: K2S2 —- (K2S + K2s5! (2) Two layers (4S) x ( 0.83) + 6KOH (water) of both (1) and (2), half a mole was used to prepare the reagent.

The fat cabbage analysis is as follows: .1 8101847> -i. -22- U—

TABLE A

Untreated Kentucky Fat Cabbage No. 9.

In received Dry Ash composition '%%% _

Moisture 2.58 Si02 54.15%

Axle 8.52 8.75 A12 ° 3 24.79%

Volatile matter 35.36 36.90 ^ e2 ^ 3 13.72%

Bonded carbon 53.54 54.95 Ti02 1.69%

Sulfur 2.62 '2.69 CaO 0.72% MJ / kg 30.126 30.924 MgO 0.85% MJ / kg minus ash fraction. 33,887 Na2 ° 0.35%

Carbon 71.60 73.50 K20 2.44%

Hydrogen 4.87 5.00 Li20 135 ppm

Nitrogen 1.59 1.63 P205 0.38%

Oxygen 8.22 8.43 S04 0.77%

Chlorides 0.22 0.23 TABLE B

Product recovered after reaction.

Density at 15.56 ° C 0.9530

Sulfur,% 0.17 .m .; .. .. MJ / kg. 42,205 ··. · MJ / 1 40,164

Carbon,% 88.62

Hydrogen,% 10.19

Sulfur,% 0.17

Nitrogen,% 0.19

Oxygen,% 0.83

'TABLE' C

Results of the distillation of the product listed in Table B.

Initial boiling point 172.2 ° C

5% 226.7 ° C

10% 252.2 ° C

20% 255.6 ° C

81018 47 -23- ι—— '

30% - - 265.6 ° C

40% 275.6 ° C

50% 281.1 ° C

60%, 290.0 ° C

70% 303.3 ° C

80% 321.1 ° C

90%, 354.4 ° C

95%, 376.7 ° C

End point 376.7 ° C

10 Found,% 96.0

Residue,% 3.7

Loss,% 0.3

TABLE D

15 Analysis of distillation product from 0-50%.

Density at 15.56 ° C 0.9287

Sulfur,% 0.15 MJ / kg 43.475 MJ / l 40.284 20 Carbon,% 87.17

Hydrogen,% 10.08

Sulfur,% 0.15

Nitrogen,% 0.18. Oxygen,% - · - - · ·· 2.42 - 25

TABLE E

Distillate analysis from 50% to end point. Density at 15.56 ° C 0.9568

Sulfur,% 0.14 30 MJ / kg 43.147 MJ / 1 41.195

Carbon,% 90.45.

Hydrogen,% 8.47

Sulfur,% 0.14, Nitrogen,% 0.31

Oxygen,% 0.63 81018 4 7> * -24- ι_— *

The above, Example III is a typical example of the conversion of fat coals into products of greater value, that is, the conversion thereof into liquid products.

It has been shown above that fuels of different carbonization, even from wood to anthracite, are an easily available source of very different hydrocarbons if the process according to the invention is used, which permits very different operating conditions and even at low temperature and under low temperature. pressure can be applied and is exothermic under certain conditions.

81018 47

Claims (26)

A process for converting solid fuels, such as coal or peat, into gaseous hydrocarbons or volatile distillates or mixtures thereof by the solid fuels and a hydrosulfide, a sulfide or a polysulfide of an alkali metal or mixtures thereof as a reactant with each other characterized in that a conversion reaction is carried out in the presence of water or hydrogen sulfide and optionally sulfur at a temperature between 50 ° C and at most 450 ° C in one or more steps, the temperature being equal in each of the steps or may be different and the reagent may be the same or different, based on the sulfur content of the reagent, and the volatile liquid distillates and hydrocarbon gases are recovered. 2. A process for converting solid fuels, such as coal, peat or wood, into gaseous hydrocarbons or volatile distillates or mixtures thereof by the solid fuels and an alkanolic solution of an alkali metal hydrosulfide, a sulfide, a poly-20 sulfide or mixture thereof reactive with each other, characterized in that a conversion reaction is carried out at a temperature of 50 ° C and higher in the presence of water as hydration water, water or steam, while also containing hydrogen sulfide, and the reaction is one or more steps is continued at a temperature up to 450 ° C, the temperature for the different steps being the same or different and the reagent for the different steps being the same or different, based on the sulfur content of the reagent and the reaction further under exothermic conditions is carried out on at least the first stage and the volatile liquid distillates and hydrocarbons terrestrial gases are recovered. 3. Process according to claim 2, characterized in that sulfur is added to the alkanolic solution of the alkali metal hydrosulfide. Process according to claim 2, characterized in that the alkali metal hydrosulfide is potassium hydrosulfide. 81 01 847 £ - ¢: -26- Process according to claim 2, characterized in that the alkali metal sulfide is sodium hydrosulfide. 6. Process according to claim 2, characterized in that the alkali metal hydrosulfide is a mixture of rubidium, potassium and sodium hydrosulfide and sulfides. Process according to claim 2, characterized in that the hydrogen sulfide is recovered. A method according to claim 2, characterized in that the fuel is a brown coal. ' Method according to claim 2, characterized in. that the fuel is a light brown coal. ltt. Process according to claim 2, characterized in that the fuel is an anthracite, partially oxidized anthracite, fat coals or flame coals. Process according to claim 2, characterized in that peat is converted. A method according to claim 2, characterized in that the alkali metal is potassium. 13. Process according to claim 2, characterized in that a part of the distillate is treated in a next step with a reagent with a higher sulfur content in the presence of hydrogen sulfide. A method according to claim 2, comprising the: feature; that the conversion is carried out at a temperature between 135 ° C and 450 ° C. 15. Process according to claim 14, characterized in that the conversion is carried out at a temperature between 170 ° C and 380 ° C. 16. Process for the continuous conversion of carbonaceous fuels, such as coal, peat or wood, into gaseous hydrocarbons and volatile distillates, characterized in that the fuel treated for expelling atmospheric oxygen is coated with reagent continuously is fed to a reaction zone, which is kept at a temperature above 50 ° C and at most at 450 ° C, the reagent for coating the fuel being a hydrosulfide, a sulfide or polysulfide of an alkali metal or mixed alkali metals or 8101847-27 mixtures of hydrosulfides, sulfides and polysulfides thereof, and hydrogen sulfide, water or steam is introduced into at least one reaction zone at a temperature between 160 ° C and 450 ° C, in at least one zone at a predetermined temperature and a predetermined reagent composition continuously converts the fuel or decomposition products thereof by 1); a predetermined reagent based on the sulfur content of the reagent, its hydrate form or its melting point or 2) mixtures of these reagents in the presence of the supplied water, steam or hydrogen sulfide, volatile and / or gaseous products from the reaction zone the hydrogen sulfide wins from the reaction zone, the ashes of the fuel from the reaction zone recover reagent and alkali metal components contained in the ash as alkali metal hydroxides, the alkali metal hydroxides react with at least a portion of the water sulfide released in the reaction and reagent and recovers the hydrogen sulfide to return it to the reaction, and supplies a sufficient amount of the reconstituted reagent to the reaction zone to continue the reaction of the fuel or decomposition products thereof with the reagent. 17. Process according to claim 16, characterized in that a first reaction zone is kept at a set predetermined temperature for the production of gaseous hydrocarbons. Process according to claim 16, characterized in that the reaction zone is kept at a temperature suitable for recovering a predetermined liquid hydrocarbon fraction. Process according to claim 17, characterized in that the gaseous hydrocarbons are treated in a second reaction zone with another reagent to prepare liquid distillates. 8101847 3-4- -28- »» »U-f · ** A method according to claim 17, characterized in that the converted fuel is brown coal. Process according to claim 17, 5, characterized in that potassium sulfide, potassium polysulfide, a potassium hydrosulfide or hydrate thereof or mixture thereof are used as reagents. Process according to claim 17, characterized in that the reaction in the first reaction zone is 10. is exothermic. 23. Process according to claim 17, characterized in that the temperature in the reaction zone is stepwise between 170 ° C and 450 ° C. 24. Process according to claim 17, characterized in that the liquid or gaseous hydrocarbon product is treated in separate steps with the alkali metal reagent with an increasing sulfur content of the reagent at discrete decreasing temperature ranges below 400 ° C but above 100 ° C . 25. A process according to claim 24, characterized in that the gaseous hydrocarbon is washed in an alkali metal hydroxide solution to remove the hydrogen sulfide from the gaseous hydrocarbon to form a conversion product with the alkali metal and the reagent is further recovered by recirculation. thereof. 26. Process according to claim 17, characterized in that a reagent of the theoretical composition K2S2 based on the material balance is used as the reagent. 27. Process according to claim 17, characterized in that anthracite or oxidized anthraclet is reacted with the reagent. 8101847